On the night of Feb. 6, 1975, Marine Reserve Squadron Capt. Larry Jividen was piloting a T-39D Sabreliner (see image above) combat trainer and utility aircraft with five Naval officer pilots on board for a special training flight. He didn't know the evening would evolve into a game of "tag" with an unidentified flying object.

Jividen hasn't spoken about that experience from nearly 40 years ago -- until now.

The nine-year Marine Corps officer -- and later commercial airline pilot -- had taken off at twilight for a two-hour roundtrip that began and ended at the Naval Air Station in Pensacola, Fla.

"At about 9 o'clock, we were descending from a high altitude -- around 33,000 feet -- and I looked off to the right side of the airplane where I saw a solid red light at our 1:00 o'clock position and altitude," Jividen told The Huffington Post.

"It was not flashing like normal anti-collision lights flash on airplanes. I thought it might be some other traffic, but I wasn't sure, so I called Pensacola Approach Control and said, 'Understand we're cleared for the approach, but we have traffic off to our right, and who's first for the approach?"

The traffic that Jividen and the other five crew members saw was mutually described as "a solid, circular object about the relative size of a kid's marble held at arm's length," Jividen recalled.

When they were informed that ground control had no other traffic in their vicinity, Jividen became concerned that the mysterious object hadn't shown up on radar. So he asked for clearance to deviate from their approach and turn directly toward the bright red UFO "just to see what it does."

As he turned toward the object, Jividen says it turned toward his plane.

"It suddenly flew from right to left, across the nose [of our plane], and just stopped at our 11:00 o'clock position. At that point, I started to speed up to see if I could close on the object, and as I [did that], it was pacing me in front. In other words, as I'd speed up, he'd speed up.

"So, I decided to descend to place the object against a star field to make sure that it was actually solid, and then I climbed so that I could silhouette the object against the Gulf of Mexico."

Jividen says the five-minute encounter came to an end when the reddish UFO flew away at a very high rate and disappeared over the horizon in the direction of New Orleans.

After the crew returned to Pensacola, Jividen filled out an incident form and that was the last he heard of the episode.

"I did some background checks on [Jividen] and one of the first things that came back was his distinguished flying crosses for doing really heroic things. He is who he says he is and very straightforward," Alexander told HuffPost.

"I don't think there's any doubt that it was something. I take him as a highly credible witness, much more so than many other ones."

Alexander's unique top-secret clearance granted him by the U.S. government gave him access in the 1980s to a variety of official documents and first-person UFO accounts. He also created a special group of top-level government officials and scientists who studied the UFO phenomenon.

In the end, Alexander determined that the U.S., indeed, had evidence pointing to UFO reality, but he couldn't find any signs that the government deliberately kept this information from the public, or that contact had been made with alien life.

"One of the things we are seeing are physical characteristics that we don't understand, capabilities that are beyond our technological options at this time, i.e. extremely fast acceleration and high-G turns that living organisms, as we know it, would not survive," he explained.

Watch these amazing pilot close encounters with UFOs:

A larger issue going on with regard to UFOs seen by military, commercial and private pilots may turn out to be potential safety hazards, says at least one respected scientist.

"My friends who are scientists say, 'Well, there's nothing to UFOs. If there were, we would have the data and we'd look at it.' That's partly a valid statement, and it's pilots who are unwittingly preventing us from getting the data to analyze scientifically," said Richard Haines, a former research scientist from NASA's Ames Research Center.

"Our objectives are to make flying safer for the flying public, specifically in regard to UAP, and we're convinced there's a potential threat posed by nearby UAP to commercial and private airplanes," Haines told HuffPost.

Working with a staff of nearly 40 people, including international affiliates, Haines is NARCAP's chief scientist. He addresses the issue of pilots who have a fear reporting UFOs or UAPs while they're still actively flying.

"To me, that's a serious inhibiting factor for scientists like myself to collect the data."

Haines suggests that the fear factor surrounding pilots doesn't have as much to do with them being afraid of the objects they encounter as it does with the fear of losing their jobs if they talk about it.

"Exactly. I don't think it's a physical fear. NARCAP comes along with the objective of trying to make flying safer for the public, and the airlines don't want to hear that because it implies it's not safe! For obvious reasons, many of the reports I have are from retired pilots."

Like the one from Jividen, who filed a report with Haines last year -- almost 40 years after the fact, but it was still impressive.

"First of all, it had a number of witnesses," said Haines. "There were six guys on board and they're not all going to mistake a common illusion.

"After several minutes [the object] didn't change size, shape or intensity, which means that it not only accelerated in front of him and stopped at his 11:00 o'clock position, but it then maintained his forward velocity. We have to ask what kind of natural phenomenon can do that?"

Former NASA scientist Richard Haines describes a harrowing pilot encounter with a UFO:

Haines still isn't sure what these unusual objects are that so many pilots over decades have reported.

"I honestly don't know, and as a scientist, I want to keep all the doors open until I've got sufficient evidence, but until that time, I'm not going to speculate."

Alexander's research leads him to at least one important conclusion about the truly unexplained UFO or UAP cases.

"If you get to the fundamental issue -- if there is an intelligence behind this, and it certainly appears to be true -- things like energy have to be key. Certainly understanding a different form of energy would be incredibly useful."

Whatever the red circular object was that Jividen and his crew encountered that night in 1975, two things made a lasting impression on him.

"First, there was no radar contact with it. Clearly, by the silhouette and movement of my aircraft, this was a solid, self-propelled object.

"I don't think our physical science is advanced enough to evaluate what these things are. There's some physical phenomena going on that we just can't clearly interpret or evaluate -- it's obviously intelligently controlled, but it may not be ET."